Apparatus and method for dispensing build material to make a three-dimensional article

Abstract

A three-dimensional article making apparatus includes a build material dispenser positioned adjacent a platform for ejecting a plurality of droplets of build material; and dispenser positioners for relatively positioning the dispenser in five degrees of freedom with respect to the platform. Accordingly, the dispenser may be rotated and flipped to permit construction of a cantilevered portion of an article without requiring support material. The dispenser positioners include a Z-direction positioner for positioning the dispenser vertically relative to the platform, an X-Y positioner for positioning the dispenser in an X-Y planar direction relative to the platform, a flip angle positioner for rotatably positioning the dispenser relative to a generally horizontal axis, and a phi angle positioner for rotatably positioning the dispenser relative to a generally vertical axis. A processor is operatively connected to the dispenser and the dispenser positioners for advancing the dispenser along a predetermined path of travel while operating or firing the dispenser to construct the three-dimensional article in successive layers or portions based upon the article defining data. Method aspects of the invention are also disclosed.

That which is claimed is: 
     
       1. An apparatus for making a three-dimensional article based upon article defining data, said apparatus comprising: a platform;   a build material dispenser positioned adjacent said platform for dispensing a plurality of droplets of build material;   dispenser positioning means for relatively positioning said dispenser with respect to said platform and comprising Z-direction positioning means for positioning said dispenser and said platform vertically relative to one another,   X-Y positioning means for positioning said dispenser and said platform in an X-Y planar direction relative to one another,   flip angle positioning means for rotatably positioning said dispenser relative to an axis generally parallel to said platform,   phi angle positioning means for rotatably positioning said dispenser relative to an axis generally perpendicular to said platform; and     a processor operatively connected to said dispenser and said dispenser positioning means for advancing said dispenser along a predetermined path of travel and controlling an orientation of said dispenser relative to said platform while operating said dispenser to construct the article based upon the article defining data.   
     
     
       2. An apparatus according to claim 1 wherein said processor comprises means for controlling said positioning means so that said dispenser is located a predetermined distance from respective target positions of the droplets of build material as said dispenser is advanced along the predetermined path of travel. 
     
     
       3. An apparatus according to claim 1 further comprising a supply of build material connected in fluid communication with said dispenser, and wherein the build material has predetermined characteristics for permitting successive dispensed droplets to adhere to and solidify upon previously dispensed and solidified build material. 
     
     
       4. An apparatus according to claim 3 wherein the predetermined characteristics of the build material permit successive dispensed droplets to adhere to and solidify upon previously dispensed and solidified build material defining a generally horizontal build direction angle to thereby permit construction of a cantilevered portion of the article. 
     
     
       5. An apparatus according to claim 4 wherein said processor further comprises means for positioning said dispenser to dispense droplets at an angle of not greater than about 45° from horizontal for the generally horizontal build direction angle while constructing the cantilevered portion of the article. 
     
     
       6. An apparatus according to claim 1 wherein said processor further comprises means for positioning said dispenser to dispense droplets along an axis defined by a build direction angle when the build direction angle is greater than about 25° from horizontal. 
     
     
       7. An apparatus according to claim 1 wherein said processor further comprises means for positioning said dispenser to dispense droplets vertically for a build direction angle of less than about 45° from vertical. 
     
     
       8. An apparatus according to claim 1 wherein said dispenser has a predetermined configuration so that a lowermost portion thereof, when positioned to dispense droplets at an angle of not less than about than about 5° from horizontal, does not intersect an imaginary plane defined by a horizontal layer of the article being constructed. 
     
     
       9. An apparatus according to claim 1 wherein said dispenser has a cylindrical body portion and a tip portion connected thereto, and wherein said tip portion is canted at a offset angle from an axis defined by said cylindrical body portion. 
     
     
       10. An apparatus according to claim 9 wherein the offset angle of said tip portion is at least about 5° from the axis defined by said cylindrical body portion. 
     
     
       11. An apparatus according to claim 1 further comprising: a reservoir for containing the build material and connected in fluid communication with said dispenser; and   a heater operatively connected to said reservoir for maintaining the build material in a liquid state.   
     
     
       12. An apparatus according to claim 11 wherein said dispenser comprises a jet having an orifice for ejecting build material therethrough, and further comprising negative meniscus means cooperating with said reservoir and said jet for forming a negative meniscus of liquid build material at the orifice of said jet. 
     
     
       13. An apparatus according to claim 11 further comprising: a conduit connected in fluid communication between said reservoir and said dispenser; and   filling means operatively connected to said reservoir for filling said conduit and said dispenser when said conduit and said dispenser are empty of build material.   
     
     
       14. An apparatus according to claim 13 further comprising emptying means connected to said reservoir for applying a vacuum to said reservoir for emptying liquid build material from said conduit and said dispenser. 
     
     
       15. An apparatus according to claim 1 further comprising test and compensation means operatively connected to said processor for sensing a test pattern of dispensed and solidified build material and for adjusting a control parameter responsive to the sensed test pattern. 
     
     
       16. An apparatus according to claim 15 wherein said test and compensation means comprises an optical source and an optical detector both mounted adjacent said dispenser and operatively connected to said dispenser positioning means. 
     
     
       17. An apparatus according to claim 1 wherein said processor further comprises means for operating said dispenser and said dispenser positioning means to construct a layer of a wall portion of the article in a plurality of side-by-side segments of dispensed and solidified build material formed in a sequence from a first side of the wall portion to a second side thereof. 
     
     
       18. An apparatus according to claim 17 wherein said processor further comprises means for operating said dispenser and said dispenser positioning means to form a next successive layer of the wall portion of the article in a plurality of side-by-side segments of dispensed and solidified build material formed in an opposite sequence from the second side of the wall portion to the first side thereof. 
     
     
       19. An apparatus according to claim 1 wherein said processor further comprises release structure means for generating a release portion of the article comprising dispensed and solidified build material being separable to thereby facilitate removal of the article from the platform. 
     
     
       20. An apparatus according to claim 1 wherein said processor further comprises base structure means for constructing a base portion of the article having a hatched wall pattern therein to increase handling strength of the article at the base portion. 
     
     
       21. An apparatus for making a three-dimensional article based upon article defining data, said apparatus comprising: a platform;   build material jetting means positioned adjacent said platform for ejecting a plurality of droplets of build material;   jet positioning means for advancing said jetting means along a predetermined path of travel and controlling an orientation of said jetting means relative to said platform in three directions and rotatably positioning said jetting means about two axes thereby defining five degrees of freedom of movement for said jetting means relative to said platform to construct the article based upon the article defining data; and   a supply of build material connected in fluid communication with said jetting means, the build material having predetermined characteristics for permitting successive ejected droplets to adhere to and solidify upon previously ejected and solidified build material defining a generally horizontal build direction angle to thereby permit construction of a cantilevered portion of the article; and   a processor operatively connected to said jetting means and said jet positioning means, said processor further comprising means for positioning said jetting means to eject droplets at an angle of not greater than about 45° from horizontal for the generally horizontal build direction angle while constructing the cantilevered portion of the article.   
     
     
       22. An apparatus according to claim 21 further comprising a processor operatively connected to said jetting means and said jet positioning means, and wherein said processor comprises means for controlling said positioning means so that said jetting means is located a predetermined distance from respective intended landing positions of the droplets of build material as said jetting means is advanced along the predetermined path of travel. 
     
     
       23. An apparatus for making a three-dimensional article based upon article defining data, said apparatus comprising: a platform;   a build material dispenser comprising a jet positioned adjacent said platform for dispensing a plurality of droplets of build material;   dispenser positioning means for advancing said jet along a predetermined path of travel relative to said platform, said dispenser positioning means comprising means for relatively positioning and orienting said jet with respect to said platform in three directions and rotatably positioning said jet about two axes thereby defining five degrees of freedom of movement for said jet means relative to said platform; and   a supply of meltable build material connected in fluid communication with said jet, the meltable build material having predetermined characteristics for permitting successive dispensed droplets to adhere to and solidify upon previously dispensed and solidified build material defining a generally horizontal build direction.   
     
     
       24. An apparatus according to claim 23 further comprising a processor operatively connected to said dispenser and said dispenser positioning means, and wherein said processor comprises means for positioning said dispenser to dispense droplets at an angle of not greater than about 45° from horizontal for the generally horizontal build direction while constructing a cantilevered portion of the article in a generally horizontal build direction. 
     
     
       25. An apparatus according to claim 23 further comprising a processor operatively connected to said dispenser and said dispenser positioning means, and wherein said processor comprises means for positioning said dispenser to dispense droplets along an axis defined by a build direction angle when the build direction angle is greater than about 25° from horizontal. 
     
     
       26. An apparatus according to claim 23 further comprising a processor operatively connected to said dispenser and said dispenser positioning means, and wherein said processor comprises means for positioning said dispenser to dispense droplets vertically for a build direction angle of less than about 45° from vertical. 
     
     
       27. An apparatus for making a three-dimensional article based upon article defining data, said apparatus comprising: a platform;   a build material dispenser having an orifice and being positioned adjacent said platform for dispensing a plurality of droplets of build material from said orifice to construct the article based upon the article defining data;   a reservoir for containing the build material in a liquid state;   a conduit connected in fluid communication between said reservoir and said dispenser; and   filling means operatively connected to said reservoir for generating a predetermined pressure waveform within said reservoir for filling said conduit and said dispenser when said conduit and said dispenser are empty of build material.   
     
     
       28. An apparatus according to claim 27 wherein said predetermined pressure waveform has a gradually increasing magnitude and ends at a relatively sharp cut-off after liquid build material is streamed from the orifice of said dispenser. 
     
     
       29. An apparatus according to claim 27 wherein said reservoir and said dispenser are relatively positioned to form a negative meniscus of liquid build material at the orifice of said dispenser. 
     
     
       30. An apparatus according to claim 27 further comprising a heater operatively connected to said reservoir for maintaining the build material in the liquid state. 
     
     
       31. An apparatus according to claim 27 further comprising emptying means connected to said reservoir for applying a vacuum to said reservoir for emptying liquid build material from said conduit and said dispenser. 
     
     
       32. An apparatus according to claim 31 further comprising power down sensing means for sensing shut-down of said heater without having first emptied said conduit and said dispenser, and means for activating said emptying means upon repowering of said heater to thereby remove solidified build material remaining in said conduit and said dispenser. 
     
     
       33. An apparatus according to claim 27 wherein said conduit is flexible and includes a coiled portion adjacent said dispenser to permit rotational movement thereof. 
     
     
       34. An apparatus according to claim 33 wherein said conduit comprises a heat spreading layer and an electrically resistive heater wire surrounding said heat spreading layer. 
     
     
       35. An apparatus for making a three-dimensional article based upon article defining data, said apparatus comprising: a platform;   a build material dispenser positioned adjacent said platform for dispensing a plurality of droplets of build material;   dispenser positioning means for advancing said dispenser along a predetermined path of travel relative to said platform;   a processor for operating said dispenser and said dispenser positioning means to construct the article based upon the article defining data, said processor further comprising test means for operating said dispenser and said dispenser positioning means to construct a test pattern of dispensed and solidified build material; and   test and compensation means operatively connected to said processor for sensing the test pattern and for adjusting a control parameter responsive to the sensed test pattern.   
     
     
       36. An apparatus according to claim 35 wherein said test and compensation means comprises optical test means for optically sensing the test pattern. 
     
     
       37. An apparatus according to claim 36 wherein said optical test means comprises an optical source and an optical detector both mounted adjacent said dispenser and operatively connected to said dispenser positioning means. 
     
     
       38. An apparatus for making a three-dimensional article based upon article defining data, said apparatus comprising: a platform;   a build material dispenser positioned adjacent said platform for dispensing a plurality of droplets of build material;   dispenser positioning means for advancing said dispenser along a predetermined path of travel relative to said platform; and   a processor for operating said dispenser and said dispenser positioning means to construct the article based upon the article defining data, said processor comprising means for operating said dispenser and said dispenser positioning means to construct a layer of a wall portion of the article in a plurality of side-by-side segments of dispensed and solidified build material formed in a sequence from a first side of the wall portion to a second side thereof, said processor further comprising means for operating said dispenser and said dispenser positioning means to form a next successive layer of the wall portion of the article in a plurality of side-by side segments of dispensed and solidified build material formed in an opposite sequence from the second side of the wall portion to the first side thereof.   
     
     
       39. An apparatus according to claim 38 wherein said processor further comprises means for constructing successive side-by-side segments in the layer in alternating directions. 
     
     
       40. An apparatus according to claim 38 wherein said processor further comprises means for operating said dispenser and said dispenser positioning means to form a next successive layer of the wall portion of the article in a plurality of side-by-side segments of dispensed and solidified build material formed in an opposite sequence from the second side of the wall portion to the first side thereof. 
     
     
       41. An apparatus according to claim 38 wherein said processor further comprises means for constructing respective successive side-by-side segments in each layer in alternating directions. 
     
     
       42. An apparatus for making a three-dimensional article based upon article defining data, said apparatus comprising: a platform;   a build material jet positioned adjacent said platform for ejecting a plurality of droplets of build material; and   jet positioning means for advancing said jet along a predetermined path of travel relative to said platform to construct the article in successive layers;   said jet having a predetermined configuration so that a lowermost portion thereof, when positioned to jet droplets at an angle not less than about than about 5° from horizontal, does not intersect an imaginary plane defined by a horizontal layer of the article being constructed.   
     
     
       43. An apparatus according to claim 42 wherein said jet has a cylindrical body portion and a tip portion connected thereto, and wherein said tip portion is canted at a offset angle from an axis defined by said cylindrical body portion. 
     
     
       44. An apparatus according to claim 43 wherein the offset angle of said tip portion is at least about 5° from the axis defined by said cylindrical body portion. 
     
     
       45. An apparatus for making a three-dimensional article based upon article defining data, said apparatus comprising: a platform;   a build material dispensing positioned adjacent said platform for dispensing a plurality of droplets of build material;   dispenser positioning means for relatively positioning said dispenser with respect to said platform; and   a processor operatively connected to said dispenser and said dispenser positioning means for advancing said dispenser along a predetermined path of travel while operating said dispenser to construct the article based upon the article defining data, said processor further comprising release structure means for generating a release portion of the article comprising dispensed and solidified build material being separable to thereby facilitate removal of the article from said platform.   
     
     
       46. An apparatus according to claim 45 wherein said dispenser positioning means comprises means for relatively positioning and orienting said dispenser with respect to said platform in three directions and rotatably positioning said dispenser about two axes thereby defining five degrees of freedom of movement for said dispenser relative to said platform. 
     
     
       47. A method for making a three-dimensional article based upon article defining data, said method comprising the steps of: advancing a build material dispenser along a predetermined path of travel relative to a platform in three directions and rotatably positioning the dispenser about two axes thereby defining five degrees of freedom of movement for the dispenser relative to the platform, and   while dispensing a plurality of droplets of build material from the dispenser to construct the article based upon the article defining data.   
     
     
       48. A method according to claim 47 further comprising the step of maintaining the position of the dispenser a predetermined distance from respective intended landing positions of the droplets of build material as the dispenser is advanced along the predetermined path of travel. 
     
     
       49. A method according to claim 47 further comprising the step of supplying build material to the dispenser, and wherein the build material has predetermined characteristics for permitting successive dispensed droplets to adhere to and solidify upon previously dispensed and solidified build material. 
     
     
       50. A method according to claim 49 wherein the predetermined characteristics of the build material permit successive dispensed droplets to adhere to and solidify upon previously dispensed and solidified build material defining a generally horizontal build direction to thereby permit construction of a cantilevered portion of the article. 
     
     
       51. A method according to claim 50 further comprising the step of positioning the dispenser to dispense droplets at an angle of not greater than about 45° from horizontal for a generally horizontal build direction angle while constructing the cantilevered portion of the article. 
     
     
       52. A method according to claim 47 further comprising the step of positioning the dispenser to dispense droplets along an axis defined by a build direction angle when the build direction angle is greater than about 25° from horizontal. 
     
     
       53. A method according to claim 47 further comprising the step of positioning the dispenser to dispense droplets vertically for a build direction angle of less than about 45° from vertical. 
     
     
       54. A method according to claim 47 further comprising the steps of: connecting a reservoir for containing the build material in fluid communication with the dispenser; and   heating the reservoir for maintaining the build material in a liquid state.   
     
     
       55. A method according to claim 54 wherein said dispenser comprise a jet having an orifice for ejecting build material therethrough, and further comprising the step of relatively positioning the reservoir and the jet to form a negative meniscus of liquid build material at the orifice of the jet. 
     
     
       56. A method according to claim 54 further comprising the steps of: connecting a conduit in fluid communication between the reservoir and the dispenser; and   filling the conduit and the dispenser when the conduit and the dispenser are empty of build material.   
     
     
       57. A method according to claim 56 further comprising the step of applying a vacuum to the reservoir for emptying liquid build material from the conduit and the dispenser. 
     
     
       58. A method according to claim 47 further comprising the steps of: forming a test pattern of dispensed and solidified build material;   sensing the test pattern; and   adjusting a control parameter responsive to the sensed test pattern.   
     
     
       59. A method according to claim 47 further comprising the step of constructing a layer of a wall portion of the article in a plurality of side-by-side segments of dispensed and solidified build material formed in a sequence from a first side of the wall portion to a second side thereof. 
     
     
       60. A method according to claim 59 further comprising the step of constructing a next successive layer of the wall portion of the article in a plurality of side-by-side segments of dispensed and solidified build material formed in an opposite sequence from the second side of the wall portion to the first side thereof. 
     
     
       61. A method according to claim 47 further comprising the step of constructing a release portion of the article comprising dispensed and solidified build material formed upon the platform and being separable to thereby facilitate removal of the article from the platform. 
     
     
       62. A method according to claim 47 further comprising the step of constructing a base portion of the article having a hatched wall pattern therein to increase handling strength of the article at the base portion.